Improvement in dampers



(fn-MERRILL'.

DAMPER.'

Patented March 28,1876.

No.175,37Z.

7] z'nesses:

Mw, @WQ/6%@ Erre" PATENT GEORGE MERRILL, OF NEWBURYPORT, MASSACHUSETTS.

IMPROVEMENT lN DAMPERS.

Specification forming part of Letters Patent No. 175,372, dated March2R, 1876; application led January 13, 1876.

-To all whom 'it may concer/n:

Be it known that I, GEORGE MERRILL, of N ewburyport, lVIassachusetts,have invented an Improvement in Valves or Dampers, of which thefollowing is a specification My invention relates to a valve or damperto be used in the tlues of boilers, stoves, furnaces, Ste., to retardthe movement of the smoke and heated vapors, in order to improve thecombustion and prevent the loss of heat resulting` from the discharge ofthe products of combustion at the usual high temperature.

The invention consists in a novel manner of constructing the valve,whereby it is rendered capable of easy adjustment and adapted to givethe current a spiral motion within the ue.

Figure l is a perspective view of my device; Fig. 2, a front-face viewof the same; Fig. 3, a rear-face view of the same in position in a ue,Fig. 4, a section of the same on the line a* Fig. 5, a face viewillustrating the form of the valve-plate and of the openings throughwhich the current passes when the .valve is mounted in a circular'opening.

The device consists of a plate, A, provided with two rear arms, B, andin some instances with a pivoted front plate, C. The plates A and C areduplicates of each other, and are made in the form of a circle cut awayon its edges in such manner that when inserted into a circular openingthere will be two peripheral curved openings, a., on opposite sides, asshown in Fig. 5, each opening increasing in width as it extends aroundthe periphery, from one end to the other, or, in other words, being ofasemi-crescent form. The arms B are made of the same size and form as theopenings a., and arranged directly behind the same, at a short distancefrom the plate A, to which latter their wide ends are joined at the wideends of the openings, as shown. The connecting portion between the rearends of the arms and the plate is preferably given an inclinationforward, as shown at c, Fig. 4, to assist in giving the currentthedesired movement. The arms may be made in one piece with the plate, ormade separately and attached thereto in any suitable manner.

In using the device, it is mounted crosswise in the liue, either rigidlyor upon a rock-shaft, so that it may be turned over edgewise out suchmanner that they receive a swift spiralmotion therein. By turning theplate O upon its pivot-,the size of the openings a may be diminishedwithout changing their form, and thereby the rapidity of the current maybe varied without affecting the spiral movement.

In boilers, furnaces, Sto., having a round smoke-flue, the device isapplied within the flue, and-the openings regulated according to thestrength of the draft. In square or rectangular tlues I insert a roundor oval tube or cylinder, D, close the space around the same, and mountthe device therein, as shown in Figs. 3 and 4. In1 return tubularboilers I divide the forward connecting-chamber by a metal plate, havingopenings in which I mount my device. Under ordinary circumstances itwill bel sufcient to have the aggregate area of the openings a fromone-quarter to one-half the area of the plate A, but it may be greaterwhen desired, and when very great area of opening is required the iiuemay be enlarged or provided with an enlarged chamber to receive a valveof greater size than the tlue.

I am aware that various devices have been employed in flues forretarding the current therein, but I am not aware that any one hashitherto combined a recessed plate and arms behind the same in themanner shown in the accompanying drawings.

Having thus described my invention, what I claim is l. The combinationof the plate A, having its edges indented, as shown, and the taperingarms B, secured rigidly to the plate immediately behind theindentations, as shown and described.

2. rIhe combination of the indented plate A, the curved tapering arms B,and the pivoted plate O, constructed and arranged to operate as shownand described.

GEO. MERRILL.

Witnesses:

E. P. BRAY, W. B. FRENCH.

